Story highlights

Kim Jong Un may have cemented his power by removing his uncle, analyst says

Jang Sung-taek was the vice chairman of North Korea's top military body

He has been removed and two of his close allies have been executed, South Korean lawmaker says

If confirmed, the move would mark a major upheaval in North Korea's leadership

It's "very likely" that North Korean leader Kim Jong Un's powerful uncle, Jang Sung-taek, has been removed from his top-level position in government, two South Korean lawmakers said Tuesday, citing a briefing from their country's intelligence service.

And two close allies of Jang -- Lee Yong-ha and Jang Soo-kee -- have been publicly executed, one of the South Korean lawmakers said at a news conference.

The lawmakers, including Cho Won-jin of the governing Saenuri Party, said this after receiving what they said was a briefing from South Korea's National Intelligence Service. CNN has not been able to independently confirm the report.

Jang Sung-taek was the brother-in-law of North Korea's previous ruler, Kim's father, Kim Jong Il. When the elder Kim died and the son succeeded him, analysts told CNN that Jang would be a power behind the throne as the younger Kim took control of the reclusive nation.

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Jang was the vice chairman of North Korea's top military body and has often been pictured beside Kim.

His removal would mark a major upheaval in North Korea's leadership since Kim succeeded his father, who died in in 2011. Some have said he may have been at the heart of an internal palace struggle, one which might have put him even at odds with his own wife, Kim Kyong Hui, according to a Time magazine report two years ago.

"If this is in fact true, the implications are pretty profound," said John Park, a Northeast Asia analyst at Harvard's Kennedy School of Government.

"Some see this as perhaps the last part of the power consolidation phase, that Kim Jong Un has in fact removed all of the old guard close to his father and is now finalizing the inserting of his own inner group," Park told CNN. But he said Jang "was seen as a force of stability" by China, North Korea's leading ally.

"I think there will be a lot of concern in Beijing right now," Park said. Jang cultivated extensive business ties with China, so his removal "also has implications in terms of making money for the regime."

But he said other analysts suspect Jang, who had fallen from favor several years ago for building his own patronage network, may have been caught trying to rebuild that system, resulting in his ouster.

It has previously been reported that Kim Il Sung -- father of Kim Jong Il and architect of the North Korean state -- disapproved of Jang's marriage into the family, according to Time.

North Korea, a state shrouded in secrecy, is involved in a protracted standoff with its neighbors and Western powers over its nuclear weapons program.

Tensions between North and South Korea soared this year as Pyongyang reacted angrily to tightened United Nations sanctions imposed in response to its latest nuclear test.

The two sides are still technically at war after the 1950-1953 Korean War ended in a mere truce, not a treaty.